docs: add OpenTelemetry integration article

See https://itnext.io/opentelemetry-otel-collectors-in-kubernetes-and-victoriametrics-stack-integration-d907ed0a15a0

Signed-off-by: hagen1778 <roman@victoriametrics.com>

docs/victoriametrics/Articles.md

@@ -114,6 +114,7 @@ See also [case studies](https://docs.victoriametrics.com/victoriametrics/casestu
 * [QCon London 2026: Wrangling Telemetry at Scale, a Guide to Self-Hosted Observability](https://www.infoq.com/news/2026/03/self-hosted-observability/)
 * [How We Made Telemetry Queries 10x Faster: Chunk-Split Caching for Metrics, Logs, and Traces](https://mirastacklabs.ai/blog/chunk-split-caching/)
 * [Claude Code: creating Kubernetes debugging AI Agent for VictoriaMetrics](https://rtfm.co.ua/en/claude-code-creating-kubernetes-debugging-ai-agent-for-victoriametrics/)
+* [OpenTelemetry: OTel Collectors in Kubernetes and VictoriaMetrics Stack integration](https://itnext.io/opentelemetry-otel-collectors-in-kubernetes-and-victoriametrics-stack-integration-d907ed0a15a0)
 
 ## Third-party articles and slides about VictoriaLogs
 

docs/victoriametrics/stream-aggregation/README.md

@@ -645,9 +645,9 @@ See also [why you shouldn't put an aggregator behind a load balancer](https://do
 
 # Troubleshooting
 
-- [Unexpected spikes for `total` or `increase` outputs](#staleness).
+- [Unexpected spikes for `total` or `increase` outputs](#data-delay-and-staleness).
 - [Excessively large values for `total*`, `increase*`, and `rate*` outputs](#counter-resets).
-- [Lower than expected values for `total_prometheus` and `increase_prometheus` outputs](#staleness).
+- [Lower than expected values for `total_prometheus` and `increase_prometheus` outputs](#data-delay-and-staleness).
 - [High memory usage and CPU usage](#high-resource-usage).
 - [Unexpected results in vmagent cluster mode](#cluster-mode).
 - [Inaccurate aggregation results for histograms](#aggregation-windows)